1. Field of the Invention
The present invention relates generally to wireless communications and more particularly to a system and method for interleaving data in a wireless transmitter.
2. Discussion of the Related Art
The Third Generation Partnership Project (3GPP) represents the joint effort of various standards setting bodies to produce globally applicable technical specifications and technical reports for the Universal Mobile Telecommunications System (UMTS). The UMTS is based on evolved Global System for Mobile Communications (GSM) core networks and the radio access technologies that they support (i.e., Universal Terrestrial Radio Access Network (UTRAN) including both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes).
The 3GPP UTRAN FDD transmitter chain includes two interleavers. The first interleaver takes an input data stream divided into code blocks, interleaves the data, and outputs the interleaved data as radio frames. Conventional transmitter designs employ a memory buffer to store the input data stream while the interleaving is performed. The memory buffer is sized to accommodate the maximum number of data bits allowed by the 3GPP specification. This memory buffer and its associated read/write logic require an amount of chip real estate and power that can be significant in terms of the transmitter design. This is particularly true where chip real estate and power usage are at a premium, such as in the design of wireless handsets.
What is needed is an improved system and method for interleaving data in a wireless transmitter wherein a savings in memory is achieved.